My Sister's Keeper
by Amber Masquerade
Summary: Frozen AU. She forced herself to become the queen of a frozen wasteland, but her little sister is determined to free her from it. Implied Ryuko/Satsuki, no incest. Rated K because this is based off of the Disney movie, so it's basically harmless.
1. Do you wanna build a snowman?

**A/N: Hello, KLK fandom, this is my first KLK fanfic! As you've read in the description, the obvious spoiler for those who have yet to watch episode 18 is that Satsuki and Ryuko are sisters (or at least half-sisters, since they share the same mother). So please, don't flame me since I've already given you a heads-up. **

**Anyways, ever since that plot twist I've been dying to make this AU. Warning: characters are somewhat OOC, especially Ragyo whom I've decided to make less sinister to fit the AU. **

**Disclaimer: I don't own Kill la Kill or any of its characters.**

**Now enjoy~ And Happy Valentine's Day!**

* * *

"Hey, Satsuki!"

The 8 year-old awoke to her younger sister bouncing on top of her while she lay in bed. Groggily, she sat up as her sister slid off of her stomach and rubbed the sleep from her eyes. "What is it, Ryuko? It's in the middle of the night," she whispered.

Ryuko's lively blue eyes blinked at her. "Do you wanna build a snowman?"

Satsuki let out a yawn. "It's too late," she frowned. "Go back to bed. We can make one tomorrow."

Her younger sister pouted. "Please, Satsuki! Just for tonight! Just for a little bit, I promise," she pleaded.

She sighed. "Mom and Dad will get mad if they hear us."

"Then we'll be very quiet," she grinned. "Please..."

After contemplating for a moment, Satsuki acquiesced to her sister's request and slipped off the side of their bed. Ryuko followed after her little sister while trying to keep her excitement contained. Slowly, Satsuki crept the door open so that her and her sister could squeeze through without being heard, and they ventured out into the empty hallway. It was too dark for Satsuki to make out where she was going, but she could hear her younger sister's footsteps bounding down the way and around the corridor. "Come one, Satsuki!" Ryuko whispered, her voice echoing across the vast walls.

"Shh!" she quieted. "Or else they'll hear you!"

The joy in Ryuko's cerulean eyes dampened a bit after she considered the consequences if their parents were to discover them sneaking out at night. "Ok..."

They lived in a mansion, where gates surrounded the outskirts to protect their castle from any intruders, and guards were always stationed outside their front doors. Their father and mother were the king and queen, after all. And as such, the two were protected at all times and rarely got to interact with other children of their age. Satsuki, one year older than her sister, was to become queen at age 18, and her sister, Ryuko, was to become the princess.

"Ok, we're here," Satsuki said as she wrapped her hand around a large gilded doorknob that led into the mansion's large ballroom.

Ryuko pushed her way through the door and run into the center of the room with a wide smile. "Do it, Satsuki!" she said excitedly.

Satsuki held out her palm tentatively. "Okay..." She gulped. "Here I go..."

It started with a small white glow that materialized and hovered over her hand. Ryuko's eyes went wide with awe as her sister willed the wisp of white to proliferate into the air and float to the ceiling, where it exploded in a magnificent burst of cold. The room was bathed in a light bluish color as snow began to flutter from the top of the ballroom and blanket the floor in a thin layer.

Ryuko held out her hand and felt a snowflake drift onto her finger and melt. "So cool..." she murmured to herself. Satsuki smiled; she was glad to see her sister so enthralled with her powers. "Hey Satsuki, look!"

She watched as her sister fell backwards into the snow and made a snow angel, giggling all the while. Her eyes softened with affection. "Wait for me!" she laughed as she trotted over to her and fell next to her. Together they laughed and ran around and danced in the white flurry as snow continued to coat the ballroom floor. Ryuko rolled a snowball into her hand and flung it at her sister, hitting her on the shoulder. Satsuki giggled and retaliated with a snowball of her own.

For a while, they had fun. Satsuki grew more confident and brave with her powers. With the flick of her wrist, she shot a wisp from her hand, which caused a mound of snow to appear suddenly. Ryuko climbed up it quickly. "Make another one!" she shouted happily. Again, Satsuki shot another blast from her hand, creating a mound even tall than the last one next to her. Ryuko leaped on top of it, her fall cushioned by the snow. "Again!" Satsuki shot another, and another as her sister jumped from one to the next.

"Wait, Ryuko!" she shouted back, trying to keep up with her sister's pace. She was going to fast for her to catch her in time.

"Catch me, Satsuki!" Blinded by joy, Ryuko still continued without stopping.

"Ryuko, stop!" her sister cried. She didn't have enough time to creat the next mound and catch her. She accidentally shot a beam into the air. Her sister fell limp as the shot hit her right on the head. "Ryuko!"

Satsuki ran to her fallen sister, who was unmoving. The snow began to melt and fade around them as she knelt down and rolled her over. Ryuko's breaths were shallow. "Ryuko, Ryuko wake up!" With tears brimming her eyes, she shook her sister gently but she did not stir. "Mom, Dad!" Feeling utterly helpless, she yelled for her parents.

The door swung open immediately and her mother and father ran in, still dressed in their night clothing. "What happened in here?" Ragyo demanded. She saw her youngest daughter lying on the floor. One of her front bangs was glimmering.

"I-I didn't mean to - I mean she was just...and I accidentally - I didn't mean to!" Satsuki stammered out through her sobs.

Her father bent down and caressed Ryuko's head. He looked up at his wife with a direness in his eyes. "She's ice cold," he said stiffly.

"I-I didn't mean to hit her..." Satsuki sniffled.

Ragyo bent down and felt Ryuko's cheek with the back of her hand. "You're right. This is bad."

"I-is there anything we can d-do? Can we help h-her...?" her older sister asked.

They exchanged glances quickly. "We have to take her to him. It's the only way," her father said solemnly. He gathered the unconscious girl in his arms and they rushed out the ballroom door. Satsuki followed them into the carriage. Silently, they rode off into the night.

* * *

The carriage bumped along down a forest-filled path and into a small clearing where a single house stood. They loaded out of the carriage and towards it. Cradling Ryuko in his arms, her father stood at the entrance and knocked hastily at the door. Satsuki hung onto her mother's hand as they waited for a response. "Soroi, Iori, we need you!" the father shouted.

Suddenly, they heard footsteps approaching them. An ancient-looking man and a younger boy with blonde hair appeared in the doorway as it opened. "What is it that you need at this hour of night?" the older man asked. He was the town's only medicine man, known for his infamous cures of all kind.

"My daughter..." he said sadly as he held out Ryuko. "She's been hit with Satsuki's magic. Is there anything you can do to help her?"

Soroi, the older man, leaned in closer to examine her. He gently laid a hand on Ryuko's forehead and his eyebrows furrowed. "Hm...this doesn't look good at all. The magic has hit her brain," he said as he examined Ryuko's condition. "Quickly, bring her inside before it completely freezes it."

They laid her on a wooden table. Satsuki stood on her tippy-toes to catch a glance at her sister, whose breaths had become shorter. Her skin was also paler than usual. The white streak on her left bang had not gone away from her navy blue hair. Soroi and his nephew were busying themselves by going through the large cabinet of potions and strange-looking concoctions. "Is there anything you can do for her?" her mother asked anxiously.

"Yes, there is one way. I know how to remove the spell from her head using magic," he said. When he was finished pouring ingredients into a flask, he whispered a spell at it. The liquid inside started to glow a bright hue of purple. "This should do it. However, we're going to have to erase her memory of Satsuki having these powers."

Satsuki looked up at him in shock. "W-why?" she asked.

"Because it would be too dangerous if she were to know. We don't want another incident like this occurring, right? You're lucky that the magic did not hit her heart, or else it would've been fatal."

Satsuki lowered her head with guilt. "Ok..."

"Now then, I will perform the spell." He took the flask and poured a bit of liquid over Ryuko's head. The liquid sunk into her head and her head began to glow faintly. Soroi whispered and the glow vanished. The streak on her head turned blood red. "There. She is better. Her memories of your powers have disappeared."

Her father stood up immediately. "Thank you so much, Soroi," he said gratefully.

"What is that red streak in her hair?" Ragyo asked.

"It is a scar that the magic has left, but it will do no harm. It will just serve as a reminder to never her see Satsuki use her powers."

Satsuki nodded sadly. However, her gaze perked up as the color of Ryuko's skin returned to normal and her breaths became regular. "I'm just glad she's alright," she said.

"Don't let this incident happen again, am I clear?" he asked Satsuki. She nodded. "Next time she won't be so lucky."

They left the house that night silently with Ryuko fast asleep in her father's arms. Satsuki still continued to cling onto her mother's hand, but not has tightly as she had done before. On the carriage ride home she stared down emptily at her hands, remembering the moment as her magic had struck her little sister. The terror she felt as she lay there limply. Silent tears slid down her cheeks. "I'm so sorry, Ryuko..." she whispered silently to herself.

* * *

**A/N: I know, I know, it's painfully OOC. For now, at least. Later, when they grow up I'll make it seem more in character, but for now I'm just gonna take advantage of them being young xD. Dunno when the next chapter will come out, but I'm pretty sure I'll get to it as soon as I stop imagining Satsuki singing "Let It Go" lol. Don't forget to leave a review and tell me what you think!**

**~Amber**


	2. Conceal, don't feel, don't let it show

One week later:

There was a series of rapid knocks on her door from outside, as well as the muffled voice of her younger sister: "Hey, Satsuki! Do you wanna build a snowman?" Ryuko asked excitedly. Huddled in a corner on the far side of the room, Satsuki sat with her legs hugged into her chest and chin resting on her kneecap.

"No," she answered, keeping her voice in a gentle tone.

"Why not?" Satsuki could hear the pout in her tone. "You've been in there for the past week! Why don't you come out and play with me?" she begged.

"I just can't, Ryuko."

"Why noooot?"

"Because..."

"Maybe I can come in there then?"

"No!"

"Why?"

"Because I said so."

"You haven't told me why."

"I just can't!" Satsuki finally yelled. "...You can't come in here ever, okay? And I can't come out there ever."

Her stubborn sister fell silent. "Can't you tell me why? We used to play a lot before, and then you just went away..."

"I can't tell you, Ryuko. Just go away," she answered quietly.

"...Okay." Satsuki waited and listened to her sister's footsteps grow fainter.

The small room in which she had locked herself up in was icy cold, and frost coated the windowsill even though it wasn't winter yet. In her week of self-imposed isolation, her powers had begun to worsen to the point where she will the small flurry of snow falling around her from the ceiling to stop. Silently, she repeated the mantra that her father had told her when she felt hopeless about her curse: "_Conceal it, don't feel it, don't let it show._"

A few hours later, Satsuki heard another knock on her door. "Go away, Ryuko - !"

"It's me, Satsuki," her father said gently. "Can you open the door?" He slipped inside and reached down to put a reassuring hand on his daughter's shoulder, but she drew back quickly.

"It's getting worse, father," Satsuki said quietly. "I can't stop it anymore."

He bent down and reached into his pocket to pull out a pair of dainty white gloves. "Here, put these on," he said as he gently slipped them on to her hands.

She frowned. "How will these help me?"

"It will help you mask your powers." She tentatively lifted her gloved hands and examined her palms; although she could feel the magic tingling in her fingers, it was suppressed within the gloves. "Remember: conceal it."

"Don't feel it," she answered back.

"Don't let it show," they finished in sync with each other.

"Okay?" he asked his daughter. She nodded with uncertainty. He bent down to give his daughter one last hopeful smile. "I know you can do it, sweetheart."

After the incident the king and queen had ordered all the front gate to be shut firmly. No one came into the castle unless it for was supplies or it was a messenger, no one left unless it was an emergency. Ryuko was left to her own devices, cooped up in the castle of vast rooms that were mostly empty, and with no other playmate. Her parents wouldn't even let her go out and play in the yard by herself because of some reason that they never had the proper words for. She had spent the last few days drearily trying to give her dolls personalities, just as she once did with her sister whenever they'd play together.

Without her sister for the first time, she felt more alone than she had ever before.

* * *

Two years later:

"Do you wanna build a snowman? Or ride our bikes around the house?" 9 year-old Ryuko asked as she knocked feverishly at her sister's door. This time she was sure that she had to come out and play.

"Go away, Ryuko," Satsuki said flatly. No longer was her voice trembling and scared as it had been two years ago. Over the time she had spent alone and locked up in that small room, her voice had become rigid and emotionless. A cold and hardened gaze had taken permanent residence in her eyes where a kinder look had once been.

"Please? You've been in there for forever! Can't we just build one snowman together? It doesn't even have to be a snowman - "

"I said leave." There was no response from her younger sister. Although she couldn't see her Ryuko's expression, she could feel her heart drop.

"...Why?" she asked quietly. "You've been locked up in that room for so long, it's like you don't exist anymore." Satsuki heard a light thump against the door. It was Ryuko leaning her forehead sadly against the wood. "It's getting lonely without you."

After a long pause, Satsuki finally mustered words. "Go away, Ryuko," she repeated.

What she refused to tell her sister was that her powers were only growing more uncontrollable and more powerful than before. Even with her gloves, whatever she laid her hand upon would almost immediately be covered with a thin layer of frost. Even though she rebelled against her powers with all of her will, she could not stop it. Scenes of the stray beam of magic hitting her little sister across the head were still fresh in her mind.

Ryuko opened her mouth to argue once more, but she found that no words would come out. "...Okay..." she finished sadly, then walked away.

* * *

Four years later:

Her hand hovered hesitantly over the door. Ryuko, already 13 years old, stood in front of her sister's door. She laid her hand on the cold wood and stood in silence for a moment. "Are you gonna come out yet, Satsuki?" she asked.

The 14 year old was sitting on the bed with a vacant look, staring at the slowly dying embers of the fire in the fireplace across the room. "No," she answered firmly.

Ryuko frowned, even though she was used to being rejected by her sister many times already. "But...it's a special day today, you know?" she said. "Can't you just come out, just once?"

She felt like a broken record that couldn't stop repeating itself. "I said no."

"Okay then," Ryuko answered. She walked away casually, but before she walked out of earshot she added in, "Just thought you'd come out for my 13th birthday."

Satsuki fell back and landed on her bedsheets and gazed up at the ceiling. Large icicles sprouted upside down with their points aimed downward as snow fluttered down from a mist that blanketed the ceiling. "I'm sorry," she murmured as she drew her knees to her chest and hugged them.

* * *

This time, the 16 year old didn't even think twice about stopping in front of her sister's door. She trotted past it without breaking stride, and entered her parent's room. They were packing for a four-month trip in the neighboring country to work out a trading deal. When she came in her father pulled her in for a hug. "Do you really have to go?" she asked, settling her chin on his shoulder.

"Don't worry, sweetie. We'll be back before you know it," he assured her.

Satsuki was waiting for them at the front door with her eyebrows furrowed and hands folded in front of her.

"What's wrong, Satsuki?" her father asked when he sensed that she was distressed.

"Please take care," she said and bowed her head respectfully.

Her father smiled softly and tried to place a gentle hand on her shoulder. She raised her head quickly and drew back, worried that she would freeze his hand or hurt him with her magic. "Satsuki, you are our next queen. The people will look to you for guidance. You mustn't let fear control you," he advised.

"I understand, father. But my powers are worsening as time passes."

"I know that, but I'm sure you'll find a way to put an end to it. Goodbye, Satsuki."

After they left, Satsuki hurried back to her room to avoid seeing Ryuko. As she finally made it to the door she quickly turned the knob, but just as she stepped inside -

"Satsuki!" Ryuko was standing at the end of the hallway with a shocked look on her face, arm extended towards her. Their eyes met for the first time in 9 years. Satsuki saw the red streak in her bangs for the first time in 9 years. Guilt overcame her suddenly, and she quickly looked down and hurried inside her room. She locked the door shut as her little sister ran to her. "Satsuki! Satsuki! C'mon, open up!" But she wasn't listening to her as she knocked at her door.

"Go away, Ryuko." She stopped her hand before it could hit against the door again.

"I just thought we could talk," she reasoned.

"I have nothing to speak to you about," she said coldly.

Ryuko balled her fists tightly. "You've been hiding in that room for 9 years now! What the hell are you talking about?!" she demanded.

"There's a certain reason why I'm in here, Ryuko," she answered evenly.

"Then why the hell aren't you telling me? Don't you think it's about time you told me _something_?"

"I'm only doing this to protect you."

"From what?!" she shot back. "All you ever do is close the door in my face anyways!"

Satsuki bit her lip to prevent her frustration from building up. "It's something that you won't ever comprehend."

"_Comprehend_ my ass! It's already been 9 years, and you're telling me that I can't understand whatever the hell your problem is?!" Ryuko loosened her fists slightly. She clenched her jaw and waited for a response.

"...Just leave."

"You can't stay in there forever!" she yelled. There was a loud bang as Ryuko kicked at the door out of frustration. The layer of ice that covered the hinges cracked and fell away. When Ryuko heard nothing coming from inside her older sister's room, she sighed and trudged away. "I just thought we could be sisters again..." she muttered to herself.

A week later, the news came to them from a messenger.

The king and queen had died while sailing home when their ship capsized during a large storm.

The funeral was short. The whole town, dressed in black, formed a solemn procession towards the royal gravesite. People asked where the future queen was, but her little sister had no answer. After everyone had a chance to pay their respects and left, Ryuko made a slow walk to her sister's room. She gave it three gentle knocks and waited in silence.

"Hey, Satsuki? I know you're in there. People are wondering where you've been," she began. Her cerulean eyes were burdened with sadness.

No response.

"Mom and Dad are gone now..." Ryuko leaned her back against the door and slid down it softly until she was sitting on the carpeted floor. "We've only got each other, huh? Just you and me..." she said sadly as a silent tear snaked down her cheek and fell on her black dress.

Still silence.

"Are you gonna come out now?"

Nothing.

"Satsuki, are you even listening to me?"

Satsuki was leaning against the door, back against the ice, knees folded to her chest. Her emotionless eyes were concentrated at the ground. No tears fell out.

Ryuko buried her head in her hands to stop the flow of tears. Her lips quivered as she tried to form a sentence. "Hey...do you wanna build a snowman...?"


End file.
